In a band saw of the kind specified the saw blade of course has a very short life in comparison with that of the elements making up the saw. More particularly, the life of the blade is generally limited by wear on its toothing, and, more rarely, by the breakage of the blade.
When the blade must be changed as a result of wear on its toothing, it must generally be cut for demounting before the saw is given a fresh blade, which must in its turn be welded in place. These operations call for relatively long interventions until the saw is restored to the operative condition. Such time is substantially further increased if the saw operates in unfavourable surroundings, since in that case the various operations have to be carried out from a distance, using suitable handling machines. In that case the time taken to replace the saw blade is all the more disadvantageous, since the saw may form one of the stations of a chain, so that the whole chain has to be stopped.
The second kind of event needing saw blade replacement, namely the breakage of the blade, has the major disadvantage in prior art band saws of being dangerous to both persons and apparatuses which may be near the saw. If the saw is in unfavourable surroundings, the apparatuses may amongst others be remote handling ones; clearly, the damage which they may suffer as a result of blade breakage may require particularly protracted and difficult operations to be performed.